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Facial expressions of emotion are innate, not learned, says
new study

San Francisco State University research finds facial expressions are
rooted in evolution

SAN FRANCISCO, December 29, 2008 -- Facial expressions of emotion are hardwired
into our genes, according to a study published today in the Journal of Personality
and Social Psychology. The research suggests that facial expressions of emotion
are innate rather than a product of cultural learning. The study is the first
of its kind to demonstrate that sighted and blind individuals use the same
facial expressions, producing the same facial muscle movements in response
to specific emotional stimuli.

The study also provides new insight into how
humans manage emotional displays according to social context, suggesting
that the ability to regulate emotional expressions is not learned through
observation.

San Francisco State University Psychology Professor David Matsumoto compared
the facial expressions of sighted and blind judo athletes at the 2004 Summer
Olympics and Paralympic Games. More than 4,800 photographs were captured
and analyzed, including images of athletes from 23 countries.

"The statistical correlation between the facial expressions of sighted
and blind individuals was almost perfect," Matsumoto said. "This
suggests something genetically resident within us is the source of facial
expressions of emotion."

Matsumoto found that sighted and blind individuals manage their expressions
of emotion in the same way according to social context. For example, because
of the social nature of the Olympic medal ceremonies, 85 percent of silver
medalists who lost their medal matches produced "social smiles" during
the ceremony. Social smiles use only the mouth muscles whereas true smiles,
known as Duchenne smiles, cause the eyes to twinkle and narrow and the cheeks
to rise.

"Losers pushed their lower lip up as if to control the emotion on their
face and many produced social smiles," Matsumoto said. "Individuals
blind from birth could not have learned to control their emotions in this
way through visual learning so there must be another mechanism. It could
be that our emotions, and the systems to regulate them, are vestiges of our
evolutionary ancestry. It's possible that in response to negative emotions,
humans have developed a system that closes the mouth so that they are prevented
from yelling, biting or throwing insults."

David Matsumoto is professor of psychology at San Francisco State University.
Matsumoto co-authored the paper with Bob Willingham from the Center for Psychological
Studies.

"Spontaneous Facial Expressions of Emotion in Congenitally and Non-Congenitally
Blind Individuals" will be published in the January issue of The Journal
of Personality and Social Psychology, Vol. 96, No.1.